"The dissemination of deliberately false information, esp. when supplied by a government or its agent to a foreign power or to the media, with the intention of influencing the policies or opinions of those who receive it" [OED], 1955, from Russian dezinformatsiya (1949), which is said to be from French désinformation, but the French word is not as old as the Russian one; see dis- + information.
Simply put, disinformation is a falsehood created with the intention to cause harm. Misinformation is also false, but created or shared without the intention to deceive others. [New York Times, Oct. 26, 2020]